// Minimal implementations to supress the warnings

int _close(int file) { 
    return -1; 
}

int _lseek(int file, int ptr, int dir) {
    return 0;
}

int _read(int file, char *ptr, int len) {
    return 0;
}

int _write(int file, char *ptr, int len) {
    return len;
}